LOS ANGELES (Reuters)
— For 33-year-old video editor and hemophilia patient Travis
Roop, being able to get life-saving infusions of a blood clotting
agent every two weeks, instead of rushing to treat a bleeding
episode, meant he could jog for the first time.

Roop was enrolled in a clinical trial testing a
long-acting treatment for hemophilia B from Denmark's Novo Nordisk.
The therapy is one of several new blood clotting agents in
development that will help hemophilia patients cut by half, or more,
the number of regular intravenous infusions they need to prevent
traumatic bleeding in their daily lives.

"It was amazing actually. It was a life-changing experience," said
Roop, who lives in the Los Angeles area. "I always avoided trauma to
my left ankle ... With this, I knew it would take care of itself."

People with hemophilia have a fault in a gene that regulates the
body's production of proteins called clotting factors. This can
cause spontaneous bleeding as well as severe bleeding following
injuries or surgery.

To avoid joint damage and other complications, patients with severe
forms of the disease need regular infusions, lasting 30 minutes or
more, of relatively short acting and very expensive clotting
factors. The number of infusions and their volume depends on the
medical status of each patient and their body weight.

Since the gene is carried on the X chromosome, hemophilia is almost
entirely a disease of men. But women can pass the gene to their
offspring. Hemophilia has often been called the "Royal Disease"
since it was carried by Britain's Queen Victoria and affected many
of the ruling families of Europe.

The U.S. Food and Drug Administration is due to decide by mid-year
whether to approve Aprolix, a new long-lasting hemophilia B clotting
factor from Biogen Idec and partner Swedish Orphan Biovitrum. Novo
Nordisk expects to file next year for regulatory approval of its
long-acting hemophilia B drug, N9-GP.

Some industry experts say these and other new treatments could help
drive down the price of existing hemophilia products, which can
total $300,000 or more a year for a single patient.

That's because Biogen does not yet market any hemophilia therapies.
In the United States, Novo Nordisk sells a drug used only by
patients who have developed antibodies to currently-used factors.

If new entrants to the hemophilia market decide to price their
longer-lasting factors in line with the overall price of the
existing shorter-acting products, the decision for patients to try
out the new factors will be relatively easy, said Dr Guy Young,
director of the Hemostasis and Thrombosis Center at Children's
Hospital Los Angeles.

"If they come in at a similar annual price, then companies that are
making recombinant drugs will be forced to drop their price," said
Dr Young, who has been involved in clinical trials of long-acting
factors.

$11 BILLION MARKET BY 2016

Worldwide, about one in 5,000 men is born with hemophilia A and one
in 25,000 men is born with hemophilia B each year.

The global market for hemophilia drugs, led by hemophilia A products
such as Baxter International's Advate and Pfizer's Xyntha, totaled
$8.5 billion in 2011 and will grow to $11.4 billion by 2016,
according to Morningstar.

Biogen Chief Executive Officer George Scangos said at an industry
conference in January that if insurance companies and other payors
view the long-lasting products as simply more convenient, they will
be priced in line with existing therapies. If they are viewed as
more beneficial, prices will be higher, he said.

Blood factor concentrates were not developed until the mid-20th
century, and up until that time people with hemophilia had a life
expectancy of less than 30 years. The last major advance in
treatment of the rare disease came in the early 1990s when
bioengineered clotting factors replaced factors derived from blood
plasma.

Factors are numbered using Roman numerals. Hemophilia A is caused by
a lack of clotting factor VIII, while hemophilia B is caused by a
lack of clotting factor IX.

The new longer-lasting hemophilia B products can be given every
10 days or two weeks, offering significant advantages for patients,
especially young children, who now need infusions every two or three
days, said Dr Marion Koerper, medical director of the National
Hemophilia Foundation and professor of hematology at the University
of California at San Francisco Children's Hospital. Koerper has not
been involved in clinical trails of longer-acting factors.

"Patients don't always get the doses they are supposed to get," she
said, noting that mornings can be hectic and parents may wait to
infuse a child at night even though factor levels should be highest
when they are running around or at school.

STRONG DEMAND SEEN FOR LONG-ACTING FACTOR IX

Biogen's Aprolix extends the duration of the factor three-fold,
while Novo Nordisk's version offers a five-fold increase, Dr Young
said. That raises the stakes for Biogen to be first to market its
product.

"There is no question that when these drugs get on the market
there will be pretty massive and quick uptake," Young said. "I
predict most (hemophilia B) patients will end up on one of these new
drugs."

Roop, the video editor, said he will seek out Biogen's therapy if it
is the first to become available, but has heard that Novo Nordisk's,
which he has already tried, works better.

For hemophilia A, the advantages of the new products are less
dramatic and uptake will be slower, Dr Young said.

An FDA decision on Biogen's longer-acting hemophilia A therapy,
Eloctate, is expected mid-year.

Baxter expects to file by the end of this year for U.S. approval of
its long-lasting hemophilia A treatment. Bayer, and CSL Behring also
have long-lasting factors in advanced stages of development. Pfizer
Inc's work in the field is still in the "discovery" stage.

Meanwhile, biotechnology companies like Sangamo BioSciences and
BioMarin Pharmaceutical are working on methods to replace defective
hemophilia genes, allowing patients to begin producing their own
clotting factor.

Biogen's Scangos acknowledged that new progress is being made in
gene therapy, particularly for hemophilia B, but believes that a
safe, effective treatment based on this method is still at least
five years away.

Roop, who has severe hemophilia B, said he was offered the option of
participating in a gene therapy trial, but decided not to take a
chance on "unproven science."

"If I can get some longer-lasting factor, maybe get down to just
once a month or once every three weeks — I would be happy with
that," he said.

Jackson Corral did not benefit during trials of the longer-lasting
treatments. The five-year-old Los Angeles area resident, who has
hemophilia A, took part in a clinical trial of Biogen's Eloctate.

His mother, Jackie Corral, cannot wait for something to work. She
prepares and infuses Jackson and his 3-year-old brother Jameson with
a factor VIII product every other morning and always stays within a
20 minute radius of both boys.

"If we did go to twice-a-week infusions that would be amazing," she
said. "That would give me so much more peace."